DESCRIPTION: This is a proposal to utilize an existing data base, the Child Health and Development Studies (CHDS), to determine the feasibility of future investigations regarding organochlorines (OCs) and polychlorinated biphenyls (PCBs) exposures and reproductive events. The study population consists of a 33 year follow-up of two generations: 1) women pregnant between 1960 and 1963 during a period of high exposure to OCs and PCBs and; 2) their adult sons who are now ages 33-36. A subset of 919 mother-child pairs has been identified through the California Department of Motor Vehicles. All but 30 of these have available maternal serum that was drawn at various times through-out the pregnancy. Maternal serum samples from 25 women considered "high risk" for OC and PCB exposure, and 25 women considered "low risk" will be analyzed for specific PCB congeners and OC levels in order to estimate range of exposures in the cohort. Methods of assessing sperm quality in these sons exposed in utero to these contaminants will be evaluated, as well as measures of fecundity in the wives/female partners of the sons.